Disturbed Ion Gradients in Brain Anoxia

Physiology ◽  
1987 ◽  
Vol 2 (2) ◽  
pp. 54-57 ◽  
Author(s):  
AJ Hansen
Keyword(s):  
Blood Flow ◽  
Sodium Chloride ◽  
Synaptic Transmission ◽  
Nerve Cell ◽  
Nerve Conduction ◽  
Brain Function ◽  
Cell Membranes ◽  
Interstitial Fluid ◽  
Potassium Conductance ◽  
Ion Gradients

Anoxia profundly affects brain function. If the blood flow is interrupted for a few minutes, the interstitial fluid shows a dramatic increase of potassium and lowering of sodium, chloride, and calcium concentrations, which lead to arrest of nerve conduction and synaptic transmission. These changes, however, cannot explain that consciousness is lost within seconds. This may be caused by activation of potassium conductance in nerve cell membranes.

Effect of chloride on renal blood flow in angiotensin II induced hypertension

1991 ◽  
Vol 69 (4) ◽  
pp. 507-511 ◽  
Author(s):  
John C. Passmore ◽  
Agnes E. Jimenez
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Sodium Chloride ◽  
Angiotensin Ii ◽  
Renal Blood Flow ◽  
Dietary Sodium ◽  
Maximum Increase ◽  
High Sodium ◽  
Low Sodium ◽  
Chloride Effect

The effect of selective dietary sodium and (or) chloride loading on blood pressure and renal blood flow (RBF) in the rat angiotensin II (AII) model of hypertension was determined. AII (200 ng/min) or saline was infused intraperitoneally. Diets were provided with either high or low concentrations of sodium, chloride or both ions for 22 days. The blood pressure of saline-treated animals was not increased by the high sodium chloride diet. Animals on a high sodium, high chloride diet had a significantly greater increase of blood pressure at 8, 15, 18, and 22 days of AII infusion compared with AII-treated animals on a low sodium, low chloride diet (p < 0.05). Selective dietary loading of either high sodium or chloride in AII-treated rats produced no greater elevation of blood pressure than AII with the low sodium, low chloride diet. Selective high dietary chloride was associated with a lower RBF in AII- and vehicle-treated rats compared with low dietary chloride. The chloride effect on RBF was greater in AII-treated animals. In conclusion, both sodium and chloride are necessary to produce the maximum increase of blood pressure in AII animals. AII enhances the decreased RBF induced by dietary chloride.Key words: angiotensin II, sodium chloride, blood pressure.

scholarly journals Computational modeling of PET tracer distribution in solid tumors integrating microvasculature

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Niloofar Fasaeiyan ◽  
M. Soltani ◽  
Farshad Moradi Kashkooli ◽  
Erfan Taatizadeh ◽  
Arman Rahmim
Keyword(s):  
Blood Flow ◽  
Computational Modeling ◽  
Interstitial Fluid ◽  
Diffusion Reaction ◽  
Surrounding Tissue ◽  
Tissue Type ◽  
Computational Domain ◽  
Interstitial Pressure ◽  
Coupled Modeling ◽  
Tumor Region

Abstract Background We present computational modeling of positron emission tomography radiotracer uptake with consideration of blood flow and interstitial fluid flow, performing spatiotemporally-coupled modeling of uptake and integrating the microvasculature. In our mathematical modeling, the uptake of fluorodeoxyglucose F-18 (FDG) was simulated based on the Convection–Diffusion–Reaction equation given its high accuracy and reliability in modeling of transport phenomena. In the proposed model, blood flow and interstitial flow are solved simultaneously to calculate interstitial pressure and velocity distribution inside cancer and normal tissues. As a result, the spatiotemporal distribution of the FDG tracer is calculated based on velocity and pressure distributions in both kinds of tissues. Results Interstitial pressure has maximum value in the tumor region compared to surrounding tissue. In addition, interstitial fluid velocity is extremely low in the entire computational domain indicating that convection can be neglected without effecting results noticeably. Furthermore, our results illustrate that the total concentration of FDG in the tumor region is an order of magnitude larger than in surrounding normal tissue, due to lack of functional lymphatic drainage system and also highly-permeable microvessels in tumors. The magnitude of the free tracer and metabolized (phosphorylated) radiotracer concentrations followed very different trends over the entire time period, regardless of tissue type (tumor vs. normal). Conclusion Our spatiotemporally-coupled modeling provides helpful tools towards improved understanding and quantification of in vivo preclinical and clinical studies.

The concept of coupling blood flow to brain function: Revision required?

1987 ◽  
Vol 22 (3) ◽  
pp. 289-297 ◽  
Author(s):  
Hans C. Lou ◽  
Lars Edvinsson ◽  
Eric T. MacKenzie
Keyword(s):  
Blood Flow ◽  
Brain Function

scholarly journals Gentiopicroside Ameliorates Diabetic Peripheral Neuropathy by Modulating PPAR- Γ/AMPK/ACC Signaling Pathway

2018 ◽  
Vol 50 (2) ◽  
pp. 585-596 ◽  
Author(s):  
Yi Lu ◽  
Jiayin Yao ◽  
Chulian Gong ◽  
Bao Wang ◽  
Piao Zhou ◽  
...  
Keyword(s):  
Blood Flow ◽  
Peripheral Neuropathy ◽  
Signaling Pathway ◽  
Conduction Velocity ◽  
Nerve Conduction ◽  
Diabetic Peripheral Neuropathy ◽  
Nerve Conduction Velocity ◽  
Nerve Blood Flow ◽  
Ppar Γ ◽  
Compound C

Background/Aims: Gentiopicroside is promising as an important secoiridoid compound against pain. The present study aimed to investigate the analgesic effect and the probable mechanism of Gentiopicroside on Diabetic Peripheral Neuropathy (DPN), and to figure out the association among Gentiopicroside, dyslipidemia and PPAR- γ/AMPK/ACC signaling pathway. Methods: DPN rat models were established by streptozotocin and RSC96 cells were cultured. Hot, cold and mechanical tactile allodynia were conducted. Blood lipids, nerve blood flow, Motor Nerve Conduction Velocity (MNCV) and Sensory Nerve Conduction Velocity (SNCV) were detected. Gene and protein expression of PPAR- γ/AMPK/ACC pathway was analyzed by reverse transcription-quan titative polymerase chain reaction (RT-qPCR) and Westernblot. Besides, PPAR-γ antagonist GW9662 and agonist rosiglitazone, AMPK antagonist compound C and activator AICAR as well as ACC inhibitor TOFA were used to further confirm the relationship between PPAR-γ and AMPK. Results: The results demonstrated that Gentiopicroside markedly ameliorated hyperalgesia with prolonged paw withdrawal latency to heat and cold stimuli and fewer responses to mechanical allodynia compared with DPN model group. Gentiopicroside regulated dyslipidemia, enhanced nerve blood flow and improved MNCV as well as SNCV. Gentiopicroside suppressed ACC expression through the activation of AMPK and PPAR-γ mediated the activation of AMPK and subsequent inhibition of ACC expression. Conclusion: In conclusion, the present study demon strated that Gentiopicroside exerted nerve-protective effect and attenuated experimental DPN by restoring dyslipidmia and improved nerve blood flow through regulating PPAR-γ/AMPK/ACC signal pathway. These results provided a promising potential treatment of DPN.

Cessation of Cerebral Blood Flow in Total Irreversible Loss of Brain Function

1969 ◽  
pp. 209-212 ◽  
Author(s):  
A. A. Hadjidimos ◽  
M. Brock ◽  
P. Baum ◽  
K. Schürmann
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Function ◽  
Irreversible Loss

Hyaluronan flux from cat intestine: changes with lymph flow

1992 ◽  
Vol 262 (2) ◽  
pp. H457-H462 ◽  
Author(s):  
R. K. Reed ◽  
M. I. Townsley ◽  
T. C. Laurent ◽  
A. E. Taylor
Keyword(s):  
Blood Flow ◽  
Major Part ◽  
Interstitial Fluid ◽  
Venous Pressure ◽  
Lymph Flow ◽  
Fluid Flux ◽  
Control Value ◽  
One Step ◽  
Experimental Group

Isolated and autoperfused ileal segments from pentobarbital-anesthetized cats were used to study turnover of hyaluronan in the intestine. A postnodal lymphatic was cannulated, and transcapillary and interstitial fluid fluxes were increased by raising venous pressure. Lymph hyaluronan concentration in control averaged 20.2 +/- 18.8 (SD) micrograms/ml (range 4.6-50) and increased with increasing lymph flow in all experiments to peak at concentrations two to three times above control values (at 15-20 mmHg increase in venous pressure). At higher lymph flows, hyaluronan concentration fell to below 5 micrograms/ml to an average of 21.3 +/- 19.5% of control value at the highest venous pressures used (30-40 mmHg). Tissue hyaluronan content fell from 349 +/- 191 micrograms/g dry wt in control to 148 +/- 78 micrograms/g dry wt (P less than 0.05) at the end of the experiment. In a second group, vasodilators were administered before elevation of venous pressure to prevent redistribution of blood flow between mucosal and muscular layers. The results were similar to those obtained above. In a third experimental group, venous pressure was elevated in one step to 30 mmHg and maintained at this level. Again, hyaluronan concentration initially increased and later fell well below control values. We conclude that a major part of the intestinal hyaluronan is easily mobilized by increased interstitial fluid flux.

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